FAQ
Frequently Asked Questions
What port and pin-count combinations does the Gigabit family offer?
32 single-port, 24 dual-port and 14 quad-port parts, with pin counts from 18 to 96.
Single-port parts are mostly 24-pin, dual-port parts cluster at 48 and 50 pins, and quad-port parts spread across 72, 88 and 96 pins. Pin count cannot be read back to port count directly — 48 pins gives two ports here but four in the100M family, because a Gigabit port needs four channels where a 100M port needs two. Dividing the internal unit count by four is more reliable. The full list is in the100/1000 BASE-T range.
Why is insertion loss a single value on some Gigabit parts and a formula on others?
The two styles define different limits: a single value is one ceiling across the whole band, while a formula gives a frequency-dependent ceiling — the two cannot be converted into each other or compared directly.
Both styles appear in this family. The formula form matches the masks printed in PHY datasheets, so no conversion is needed when comparing. For a link budget, evaluate the part's own expression at the working frequency, keeping the sign and the Max/Min qualifier intact. Applying one part's band or formula to another is a common and costly error. Each part's definition is on its own datasheet, linked from the100/1000 BASE-T range.
What PoE grades does the Gigabit family cover?
This is the broadest PoE range in the category — from no power capability at all, through standard PoE and PoE+, to several current grades for four-pair power.
Of the 70 parts, around six in ten carry no power capability, and the rest spread across a number of current grades, the highest well above the ceiling in other families. Settle the IEEE class before comparing current figures, because the class sets the PSE-side power ceiling and the number of powered pairs. Note also what a figure applies to — "each channel" and "full channels" are different statements, and neither should be multiplied out. Grades are shown per part in the100/1000 BASE-T range.
What isolation grades does the Gigabit family offer?
The large majority sit at the standard grade, with a handful spread across four higher grades, the highest of which is the ceiling for the whole category.
Where a project needs more than the standard grade the choice narrows to single digits, so this belongs early in selection rather than after the package is fixed. As with temperature, isolation grade does not show in package parameters, and one land pattern may carry both a standard-grade and a high-grade part. Send us the safety clause and VOOHU will confirm what is available. Ratings are listed per part in the100/1000 BASE-T range.
What temperature grades does the Gigabit family cover, and where do automotive parts sit?
Commercial and industrial wide-temperature grades split the family roughly in half, with three parts reaching wider still, among them the only automotive-related part in this catalogue.
That part's datasheet uses the wording "AEC-Q200 tested", which is not the same as being AEC-Q200 certified — AEC-Q200 is a qualification specification rather than a certificate issued by a body, and the vehicle maker or Tier 1 reviews the evidence at design-in. Before submitting automotive documentation, request the test report and confirm the covered tests, grade and lot meet the review criteria. Temperature grades are listed per part in the100/1000 BASE-T range.
How does "operating temperature includes temperature rise" change a thermal budget?
When that clause is present, the upper limit is the component's own temperature boundary rather than an allowable ambient, so self-heating must not be added on top of the stated maximum.
Both styles appear in this family: where the clause is stated, the figure already accounts for the rise during operation; where it is absent, the figure should be read as a component operating range. The two cannot be compared as bare numbers. No derating curve is published, so measure the component surface temperature in the finished product under the worst airflow case and confirm it stays below the limit. Each part's wording is on its own datasheet, linked from the100/1000 BASE-T range.
